Power conversion system for wireless communication systems

Abstract

A power conversion system for a power communications system, the power conversion system coupled to a power supply to supply input power over a power cable to remote radio heads (RRHs). The power conversion system comprises an input that receives input power from the power supply, and an output coupled to the power cable. A control module is configured to monitor power information, the power information including an input voltage of the power input, a current measurement of the input power, and a resistance of the power cable. One or more DC-DC converters is coupled to the control module and configured to generate an output voltage at the output, the output voltage generated by adding to the input voltage, a supplemental voltage determined from the monitored power information to compensate for a voltage decrease on the power cable.

What is claimed is: 
     
         1 . A power conversion system coupled to a power supply that supplies power over a power cable connected to remote radio heads (RRHs), the power conversion system comprising:
 an input that receives input power from the power supply, and an output coupled to the power cable;   a control module configured to monitor power information, the power information including a current measurement of the input power, and a resistance of the power cable; and   one or more DC-DC converters coupled to the control module and configured to generate a output voltage at the output, the output voltage generated by adding to the input voltage, a supplemental voltage determined from the monitored power information to compensate for a voltage decrease on the power cable.   
     
     
         2 . The power conversion system of  claim 1 , wherein the power information further includes: a top voltage at an input to the RRHs, and a target voltage at a power input of the RRHs. 
     
     
         3 . The power conversion system of  claim 2 , wherein the control module is further configured to use at least a portion of the power information determine a voltage drop on a DC cables and to signal the one or more DC-DC converters to adjust the output voltage of the one or more DC-DC converters to compensate for any input voltage decrease to maintain the input voltage at the RRHs at a relative constant level. 
     
     
         4 . The power conversion system of  claim 2 , wherein adjusting the output voltage (V OUT ) further comprises: adding to an input voltage (V IN ) of the input power, a supplemental voltage (V SUPP ): 
       
         
           
             
               
 
               
                 
                   V 
                   OUT 
                 
                 = 
                 
                   
                     V 
                     IN 
                   
                   + 
                   
                     
                       V 
                       SUPP 
                     
                     . 
                   
                 
               
             
           
         
       
     
     
         5 . The power conversion system of  claim 4 , further comprising calculating the supplemental voltage (V SUPP ) using the power information including the input voltage (VIN), the input current measurements (I IN  and I MOD ), a cable resistance (R cable ), and a target voltage (V target ) at a power input of the RRHs: 
       
         
           
             
               
 
               
                 
                   V 
                   SUPP 
                 
                 = 
                 
                   Vtarget 
                   + 
                   
                     
                       ( 
                       
                         
                           I 
                           IN 
                         
                         - 
                         
                           I 
                           MOD 
                         
                       
                       ) 
                     
                     * 
                     Rcable 
                   
                   - 
                   
                     
                       V 
                       IN 
                     
                     . 
                   
                 
               
             
           
         
       
     
     
         6 . The power conversion system of  claim 2 , wherein the resistance of the power cable is determined by calculating a resistance of each DC circuit in the power cable based on the top voltage at the RRHs, the current measurements of the input power, and the output voltage. 
     
     
         7 . The power conversion system of  claim 6 , further comprising: wherein the resistance of the power cable is determined by receiving resistance information that is input by a user. 
     
     
         8 . The power conversion system of  claim 1 , further comprising an enclosure that has slots to receive at least one pluggable module containing the one or more of one or more DC-DC converters. 
     
     
         9 . The power conversion system of claim  9 , wherein the power conversion system is implemented in a 2 U rack configuration. 
     
     
         10 . A power conversion system, comprising:
 a DC-DC converter configured to receive a power input including an input voltage (V IN ) from a power supply and generate an output voltage (V OUT ) on a DC cable to power at least one remote radio head (RRH);   a control module configured to:
 i) estimate a cable resistance (R cable ) of the DC cable based on power information, the power information including: the output voltage (V OUT ), a top voltage on the power cable at the RRHs, input current measurements of the power input, the input current measurements comprising an input current (I IN ) measured on an input of the power conversion system, and an input current (I MOD ) measured on an input to the DC-DC converter; 
 ii) determine a voltage drop on the DC cable based on the cable resistance (R cable ) and the input current measurements (I IN  and I MOD ); and 
 ii) adjust the output voltage (V OUT ) of the DC-DC converter by adding by adding to the input voltage (V IN ), a supplemental voltage (V SUPP ) so that the output voltage (V OUT ) compensates for the voltage drop: 
   
       
         
           
             
               
 
               
                 
                   V 
                   OUT 
                 
                 = 
                 
                   
                     V 
                     IN 
                   
                   + 
                   
                     
                       V 
                       SUPP 
                     
                     . 
                   
                 
               
             
           
         
       
     
     
         11 . The power conversion system of  claim 10 , wherein the estimation of the cable resistance is performed by dividing a difference between the top voltage measurements and the base output voltage (V OUT ) by the estimated current (I OUT ). 
     
     
         12 . The power conversion system of  claim 11 , further comprising calculating the supplemental voltage (V SUPP ) using the power information including the input voltage (V IN ), the input current measurements (I IN  and I MOD ), the cable resistance (R cable ), and a target voltage (V target ) at a power input of the RRHs: 
       
         
           
             
               
 
               
                 
                   V 
                   SUPP 
                 
                 = 
                 
                   Vtarget 
                   + 
                   
                     
                       ( 
                       
                         
                           I 
                           IN 
                         
                         - 
                         
                           I 
                           MOD 
                         
                       
                       ) 
                     
                     * 
                     Rcable 
                   
                   - 
                   
                     
                       V 
                       IN 
                     
                     . 
                   
                 
               
             
           
         
       
     
     
         13 . The power conversion system of  claim 10 , wherein the control module first estimates a current (I OUT ) of the power conversion system by subtracting the input current (I MOD ) to the DC-DC converter from the input current (I IN ) of the DC-DC converter. 
     
     
         14 . The power conversion system of  claim 10 , wherein a value of the input voltage (V IN ) is reduced due to the usage of a battery, the control module further configured to: increase the output voltage (V OUT ) to compensate for the reduced input voltage in addition to the voltage drop on the DC power cable. 
     
     
         15 . The power conversion system of  claim 14 , wherein the supplemented voltage (V SUPP ) equals the reduced voltage drop due to the battery and the voltage drop on the DC power cable.